Herbicidal Mixture, Comprising an Imidazolinone Herbicide and an Adjuvant

ABSTRACT

A herbicidal mixture, comprising
     a) a herbicidally effective amount of an imidazolinone herbicide selected from the group consisting of imazamox, imazapic, imazapyr;   b) an adjuvant comprising at least one of the following components: a partial phosphoric ester or a partial sulfuric ester of a monohydroxy-functional polyalkyl ether
       and optionally   
       c) a further additive.

The present invention relates to a herbicidal mixture of animidazolinone herbicide and an adjuvant.

The imidazolinone herbicides of the present invention encompass:imazamox, imazapic, imazapyr, all of those are further specified in e.g.C. D. S. Tomlin, “The Pesticide Manual”, 13^(th) Edition, BCPC (2003),Index 5, 1337-1344 andhttp://www.hclrss.demon.co.uk/index_cn_frame.html.

Referring to imidazolinone herbicides or specific imidazolinoneherbicide species in this application shall mean the compounds asmentioned above, as well as their a) salts, e.g. salts of alkaline orearth alkaline metals or ammonium or organoammonium salts, for instance,sodium, potassium, ammonium, preferably isopropyl ammonium etc.; b)respective isomers, e.g. stereo isomers such as the respectiveenantiomers, in particular the respective R- or S-enantiomers (includingsalts, ester, amides), c) respective esters, e.g. carboxylic acidC1-C8-(branched or non-branched) alkyl esters, such as methyl esters,ethyl esters, isopropyl esters, d) respective amides, e.g. carboxylicacid amides or carboxylic acid C1-C8-(branched or non-branched) mono ordi alkyl amides, such as dimethylamides, diethylamides, diisopropylamides or e) any other derivative which contains the above imidazolinonestructures as structural moiety.

In particular the term imidazolinone herbicide or reference to specificimidazolinone herbicides herein, such as, imazamox, imazapic, imazapyr,shall include alkylammonium salts, preferably isopropylammonium salts,for example diisopropylammonium- or monoisopropylammonium salts.

Further suitable imidazolinone herbicides are the R-isomers, e.g.R-imazamox, R-imazapic, R-imazapyr, in particular R-imazapyr. Thesecompounds are known e.g. from U.S. Pat. No. 5,973,154 B (AmericanCyanamid Company) and U.S. Pat. No. 6,339,158 B1 (American CyanamidCompany).

EP 0 356 812 A2 discloses tank-mix compositions of certain herbicides,including imazaquin and imazethapyr, with low foaming nonionicalkylpolyoxyalkylene polyethers and for example anionic surfactants suchas partial phosphate esters of monohydroxy-functional polyoxyalkyleneethers.

EP 0 356 812 A is silent as to weed control in the presence of trees.

It is an object of the present invention to provide a herbicidal mixturewhich comprises herbicidal mixtures of an imidazolinone herbicide and anadjuvant and whose herbicidal activity is higher than the activity ofthe pure active compound.

This object was achieved by a herbicidal mixture, comprising

-   a) a herbicidally effective amount of an imidazolinone herbicide    selected from the group consisting of imazamox, imazapic, imazapyr,-   b) an adjuvant comprising at least one of the following components:    a partial phosphoric ester or a partial sulfuric ester of a    monohydroxy-functional polyalkyl ether    -   and optionally-   c) further additives.

The herbicidal mixture according to the invention displays a synergisticeffect and is selective for those crop plants which are also compatiblewith the individual compounds.

Suitable adjuvants b) comprise partial phosphoric ester or partialsulfuric ester of a monohydroxy-functional polyalkyl ether.

These partial esters are prepared by methods well known to those skilledin the art, for example by reacting one of the well known andcommercially monohydric polyoxyalkylene ethers with sulfuric acid orphosphoric acid or their chemical equivalents. The sulfate ester soobtained consist predominantly of the half ester (mono ester) while thephosphate esters generally contain both, mono- and diesters. Also usefulare the simple salts of these surfactants, for example, the alkalimetal, alkaline earth metal or ammonium salts. The sulfate esters may beprepared for example by reacting a suitable mono-functionalpolyoxyalkylene ether with sulfuric acid or its chemical equivalent,preferably sulfamic acid or sulfurtrioxide. Phosphate esters aredescribed, for example, in U.S. Pat. No. 5,877,112 column 2, lines 32 to67 (included herein by reference) and may be prepared, for example, byreaction of the monofunctional polyoxyalkylene ether with phosphoricacid, diphosphorus pentoxide, polyphosphoric acid or phosphorusoxytrichloride. Methods of preparation are described in the treatise“Nonionic Surfactants”, Martin Schick, Ed., Marcel Dekker, New York,1967, chapter 11, pages 372-394.

Suitable partial phosphoric esters and partial sulfuric esters of amonohydroxy-functional polyalkylene ethers are those whose polyalkyleneether radicals can be prepared by oxalkylation of long-chain alcoholssuch as C₁₀-C₂₀-alkanols, preferably C₁₀-C₁₆-alkanols, with alkyleneoxides such as ethylene oxide, propylene oxide or butylene oxide. Thealkylene oxides can be employed as a mixture, or else successively, forpreparing block copolymers.

Preference is given to polyalkylene ethers having a C₁₀-C₁₆alkyl chainwith 10 to 15 mol of ethylene oxide units and 1 to 10, preferably 2 to 6mol of propylene oxide units.

Preferred products are Klearfac™ AA 270 of BASF Corporation andLutensit® A-EP from BASF Aktiengesellschaft.

The herbicidal mixture according to the invention comprises thecomponents a) and b) in the following amounts (by weight-%): 1 to 99% byweight of the component a) and 1 to 99% by weight of the component b).Preferred ratios are: 20 to 80% by weight of the component a) and 20 to80% by weight of the component b). Very preferred ratios are: 45 to 55%by weight of the component a) and 45 to 55% by weight of the componentb). Here, the components together are 100% by weight.

In addition to component b), further additives c) can be used, alone orin combination, for example:

c1) castor oil based surfactant. This is a triglycerideethoxylates—nonionic surfactant. Ethoxylated triglycerides are nonionicpolyoxyethylene surfactants usually prepared by the condensation oraddition of ethylene oxide to a hydrophobic compound, castor oil. Castoroil is a triglyceride (ester) of fatty acids with the approximatecomposition of 90% ricinoleic acid, an 18-carbon acid having a doublebond in the 9-10 position and the hydroxyl group on the 12^(th) carbon.The remaining 10% consists of linoleic, oleic, stearic, palmitic,dihydroxystearic, linolenic and eicosanoic acids;c2) alkyl polyoxyalkylene polyethers. These compounds are known and manyare commercially obtainable. These compounds are described, for example,in U.S. Pat. No. 5,238,604, col. 2, lines 43 to 68. Suitable alkylpolyoxyalkylene polyethers are those which can be prepared byoxalkylation of C₁₀-C₁₂-alkanols with alkylene oxides such as ethyleneoxide, propylene oxide or butylene oxide. Preference is given to alkylpolyoxyalkylene polyethers having a C₁₀-C₂₅alkyl chain, preferablyC₁₂-C₂₀-alkyl chain, with an EO/PO block copolymer, such as, forexample, Plurafac® LF, BASF AG, Plurafac RA 20® (BASFAktiengesellschaft) and in particular Pluraflo L1060® (BASFCorporationn).

The present invention also extends to herbicidal compositions whichcomprise the components a) and b), optionally c), at least one liquidand/or solid carrier and, if desired, at least one further additive d).

Said herbicidal compositions can be a herbicidal finished formulation,preferably a herbicidal finished liquid formulation, most preferably aherbicidal finished aqueous liquid formulation.

However, these herbicidal compositions can also be tank-mixes which aremade from the herbicidal mixture according to the invention orpreferably from the herbicidal finished formulation according to theinvention.

Such a tank mix is usually obtained by diluting the pre-mixed herbicidalmixture a) plus b) and optionally c) or preferably by diluting thefinished formulation according to the invention, usually with water.Optionally further additives d) may be added before or after the mixingor dilution step.

Examples and brands of further additives d) are described in FarmChemicals Handbook 1997; Meister Publishing 1997 p. C10 “adjuvant” or1998 Weed Control Manual p. 86.

Preferably the tank-mix is prepared shortly before the application ofthe herbicidal composition.

A preferred further additive d) is methylated seed oil, such as methylcaprylate-caprate, methyl laurate, methyl myristate, methyl palmitate,methyl stearate, methyl oleate, methyl coconate, methyl sunflowerate,methyl canolate, and methyl soyate, in particular the one with the tradename Sunit II The methylated seed oils are known in the art and forexample described in Fourth International Symposium on Adjuvants ForAgrochemicals, Melbourne Australia, 1995, organized by The Counsel ofAustralian Weed Science Societies, Edited by Robyn E. Gaskin.

Methyl esters are usually produced by transesterification process: anatural fat (animal derived) or oil (vegetable derived) is combined withcatalyst and methanol to yield, after refining, the whole methyl esterand a glycerine co-product. The whole methyl ester contains esters ofall the fatty acids present in the fat or oil. It can be used as such ormay be fractionally distilled into its components. Methylated seed oilsare either saturated or unsaturated esters. The saturated esters rangeusually from C6 (caproate) to C18 (stearate), the unsaturated estersrange usually from C14 (myristoleate) to C18 (linolenate).

Sunit II™ is a combination of methyl esters primarily methyl oleate witha proprietary nonionic surfactant.

The methylated seed oil can be added in amounts (all weight-%) from 0.5%to 50% preferably 1% to 20%, most preferably 1% to 10%, very mostpreferably 0.5% to 5%, all of those referring to % of adjuvant in water.

A herbicidal finished formulation according to the invention doesinclude directly sprayable aqueous solutions, suspensions,highly-concentrated aqueous, oily or other suspensions or dispersions,emulsions, oil dispersions, pastes, materials for spreading, which canbe applied by means of spraying, atomizing, spreading or pouring.

Suitable inert additives (auxiliaries), for example mineral oilfractions of medium to high boiling point such as kerosene and dieseloil, furthermore coal tar oils and oils of vegetable or animal origin,aliphatic, cyclic and aromatic hydrocarbons, e.g. paraffins,tetrahydronaphthalene, alkylated naphthalenes and their derivatives,alkylated benzenes and their derivatives, alcohols such as methanol,ethanol, propanol, butanol and cyclohexanol, ketones such ascyclohexanone, strongly polar solvents, such as N-methylpyrrolidone andpreferably water.

Aqueous use forms can be prepared from emulsion concentrates,suspensions, pastes, by adding water. To prepare emulsions, pastes oroil dispersions, the substances, as such or dissolved in an oil orsolvent, can be homogenized in water by means of wetting agent,tackifier, dispersant or emulsifier. However, it is also possible toprepare concentrates composed of active substance, wetting agent,tackifier, dispersant or emulsifier and, if appropriate, solvent or oil,and these concentrates are suitable for dilution with water.

The concentrations of the herbicidal mixture a) and b) according to theinvention in the herbicidal finished formulations can be varied withinwide ranges. In general, the herbicidal finished formulations comprisefrom 0.01% to 95% by weight, preferably 0.5% to 90% by weight, verypreferably 45% to 55% by weight of the herbicidal mixture a) and b)according to the invention.

A suitable herbicidal finished formulation according to the inventiondoes in addition to the herbicidal mixture a) and b) comprise water.

Another suitable herbicidal finished formulation according to theinvention does in addition to the herbicidal mixture a) and b) comprisewater and an antifreeze agent. Anti-freeze agents are known in the artand include for example isopropylglycol, diisopropyl glycol, ethyleneglycol.

Another suitable herbicidal finished formulation according to theinvention does in addition to the herbicidal mixture a) and b) comprisewater and an antifreeze agent, and the component a) being imazapyr,imazamox, imazapic or mixtures of those imidazolinone herbicides and thecomponent b) being a partial phosphoric ester of amonohydroxy-functional polyalkyl ether, for example Klearfac® AA 270, aproduct of BASF Corporation, with or without alkyl polyoxyalkylenepolyether.

A preferable herbicidal finished formulation according to the inventiondoes in addition to the herbicidal mixture a) and b) comprise water andan antifreeze agent, and the component a) being imazapyr, imazamox ormixtures of those imidazolinone herbicides and the component b) being apartial phosphoric ester of a monohydroxy-functional polyalkyl ether,for example Klearfac® AA 270, a product of BASF Corporation, with orwithout alkyl polyoxyalkylene polyether.

Another preferable herbicidal finished formulation according to theinvention does in addition to the herbicidal mixture a) and b) comprisewater and an antifreeze agent, and the component a) being imazapyr andthe component b) being a partial phosphoric ester of amonohydroxy-functional polyalkyl ether, for example Klearfac® M 270, aproduct of BASF Corporation, with or without alkyl polyoxyalkylenepolyether.

A very preferable herbicidal finished formulation according to theinvention does in addition to the herbicidal mixture a) and b) comprisewater and an antifreeze agent, and the component a) being imazapyr,imazamox, or mixtures of those imidazolinone herbicides and thecomponent b) being a partial phosphoric ester of amonohydroxy-functional polyalkyl ether, for example Klearfac® AA 270, aproduct of BASF Corporation, wherein the components are contained in thefollowing amounts, weight-% referring to the herbicidal finishedformulation:

a) Imazapyr from 5% to 40%, preferably 10% to 20%; b) a partialphosphoric ester of a monohydroxy-functional polyalkyl ether, forexample Klearfac® AA 270, a product of BASF Corporation from 5% to 50%,preferably 15% to 25%; and antifreeze agent: from 1% to 10%, preferably1% to 5%; and water of the amount, which sums up to 100%.

The herbicidal finished formulation according to the invention doesusually have a pH value in range from 6.0 to 8.0, in particular of from6.8 to 7.2.

A big advantage of the herbicidal finished formulation according to theinvention in which the imidazolinone herbicide is present in form of itssalts, preferably of its ammonium salts and in particular of itsmonoisopropyl ammonium salt is that it does not need additional acid tobuffer the formulation.

The herbicidal finished formulation according to the invention isgenerally prepared according to methods known in the art for thespecific type of said formulations, see for example Surfactants &Specialties for Plant Protection Rhone-Poulenc (now Rhodia) 3^(rd)edition, 1994.

An example for a good method for the preparation of an aqueousherbicidal finished formulation according to the invention is asfollows:

Usually about 90% of the total amount of water is added to the reactorvessel (about 10% is used at the end for active ingredient adjustment),then an amine, for example, mono-isopropylamine is added to the reactorcontaining water, then the component a), for example imazapyr orimazamox is added to the reactor and blended until the reaction with theamine is complete, then the anti-freeze agent, for example, propyleneglycol is added to the reactor and blended, then the additive b), forexample Klearfac® M 270 is slowly added to the reactor and blended untilthe pH is adjusted to 6.8 to 7.2. The batch is analyzed and theremaining water is added to achieve the active ingredient content of forexample, 22.0%. All steps are usually conducted by a temperature of 20to 25° C., if necessary by cooling the reaction vessel.

The components a) and b) are usually applied to the plants, theirenvironment and/or seeds jointly. It is preferable to apply the activeingredients simultaneously. However, it is also possible to apply themseparately.

The components a) and b) can be applied by using a herbicidal finishedformulation or a tank-mix prepared as described above, preferably byusing a herbicidal finished formulation.

Moreover, it may be advantageous to apply the herbicidal mixtures,herbicidal finished formulations or herbicidal compositions according tothe invention with additional other crop protection agents, for examplewith pesticides or agents for controlling phytopathogenic fungi orbacteria. Also of interest is the miscibility with mineral saltsolutions which are employed for treating nutritional and trace elementdeficiencies. Non-phytotoxic oils and oil concentrates can also beadded, as described above.

The herbicidal mixtures, herbicidal finished formulations or herbicidalcompositions according to the invention, can be employed, for example,in the form of directly sprayable aqueous solutions, suspensions, alsohighly-concentrated aqueous, oily or other suspensions or dispersions,emulsions, oil dispersions, pastes, materials for spreading or, by meansof spraying, atomizing, spreading or pouring. Preferred is theapplication of directly sprayable aqueous solutions.

The use forms depend on the intended purposes; in any case, they shouldguarantee the finest possible distribution of the active ingredientsaccording to the invention.

The herbicidal mixtures, herbicidal finished formulations or herbicidalcompositions according to the invention can be applied pre- orpost-emergence. It is advantageous to apply the herbicidal mixtures,herbicidal finished formulations or herbicidal compositions according tothe invention post emergent when the crop has in general 1 to 6 leaves.

If the imidazolinone herbicide active ingredients are less welltolerated by certain crop plants, application techniques may be used inwhich the herbicidal compositions are sprayed, with the aid of the sprayapparatus, in such a way that they come into as little contact, if any,with the leaves of the sensitive crop plants while reaching the leavesof undesirable plants which grow underneath, or the bare soil(post-directed, lay-by).

In the case of a post-emergence treatment of the plants, the herbicidalmixtures, herbicidal finished formulations or herbicidal compositionsaccording to the invention are preferably applied by foliar application.Application may be effected, for example, by usual spraying techniqueswith water as the carrier, using amounts of spray mixture of approx. 47to 473 I/ha. The mixtures or compositions may also be applied by theso-called “low-volume” and “ultra-low-volume” methods.

The rate of application of pure active ingredient a), i.e. withoutformulation auxiliaries, amounts in general to 0.1 to 2000 g/ha,preferably 1 to 1500 g/ha, in particular 5 to 1000 g/ha, of activesubstance (a.s.), depending on the intended aim, the season, the targetplants and growth stage.

The herbicidal mixtures, herbicidal finished formulations or herbicidalcompositions according to the invention can effect very good control ofgrass weeds and broadleaf weeds in many crops without damaging the cropplants, an effect observed especially at low rates of application.

Suitable crops are for example maize, brassica napus (canola, oilseedrape), sunflower, legumes, sugar cane, and soya, or cereals (for examplewheat, rye).

The herbicidal mixtures, herbicidal finished formulations or herbicidalcompositions according to the invention can advantageously been used tovery good control undesired vegetation in non-crop areas such as roads,railroads, turf, utility lines, and in particular in areas in whichtrees are present. The herbicidal mixtures, herbicidal finishedformulations or herbicidal compositions according to the invention arepreferably used in forestry.

Undesired vegetation in non-crop areas which is controlled by theherbicidal mixtures, herbicidal finished formulations or herbicidalcompositions according to the invention does include the followinggrasses of Table 1

TABLE 1 Annual bluegrass (Poa annua) Bahiagrass (Paspatum notatum)Barnyardgrass (Echinocloa crus-gall) Beardgrass (Andropogon spp.)Bermudagrass (Cynodon dactylon) Big bluestern (Andropogon gerardi)Broacleaf sinalgrass (Brachiaria platyphylia) Canada bluegrass (Poacompressa) Cattal (Typha spp.) Cheat (Bromus secalinus) Congograss(Imperata cylindrica) Crabgrass (Digitaria spp.) Crowfootgrass(Dactyloclenium aegyptium) Dallisgrass (Paspatum dilatatum) Downy brome(Bromus tectorum) Fall panicum (Panicum dichotomiflorum) Feathertop(Pennisetum vilosum) Fescue (Festuca spp.) Foxtail (Setaria spp.) Giantreed (Arundo donax) Goosegrass (Enusine indica) Guineagrass (Panicummaximum) Italian ryegrass (Lolium multiflorum) Itchgrass (Rottboliaexaltata) Johnsongrass (Sorghum haltepense) Junglerice (Echinochloacolorum) Kentucky bluegrass(Poa pratensis) Lovgrass (Eragrostis spp.)Orchardgrass (Dactytis glomerata) Panicum spp. Paragrass (Brachiariamutica) Phragmites (Phragmites australis) Praline cordgrass (Spartinapectinata) Prairie threeawn (Aristida oligantha) Quackgrass (Agropyronrepans) Reed canary grass (Phataris arundinacea) Saltgrass (Distichisstricta) Sand dropseed (Sporobolus cyptandrus) Sandbur (Cenchrus spp.)Smooth brome (Bromus inermis) Sprangletop (Leptocloa spp.) Timothy(Pheum pratense) Torpedograss (Panicum repens) Vaseygrass (Paspatumurvilli) Wild barley (Hordeum spp.) Wild oats (Avena fatua) Wiresternmuhly (Muhlenbergia frondosa) Witchgrass (Panicum capillare) Woollycupgrass (Eriochloa wilosa)

And the following broad leaf weeds of Table 2:

TABLE 2 Arrowwood (Pluchea sericea) Broom snakeweed (Gutlerraziasarothrae) Bull Thistle (Cirsium vulgare) Burclover (medicago spp.)Burdock (Arctium spp.) Camphorweed (Heterotheca subaxilaris) Carolinageranium (Geranium carolinarum) Carpetweed (Mulogo verticitata)Chickweed, moussear (Cerastium vulgatum) Clover (Trifolium spp.)Cocklebur (Xanthium strunarium) Common chickweed (Stellaria media)Common ragweed (Ambrosia artemisifolia) Cudweed (Gnaphalium app.)Dandelion (Taraxacum officinale) Desert camelthorn (Alhegi pseudahagi)Diffuse knapweed (Cantauree diccusal) Dock (Rumex spp.) Dongfennel(Eupatorium capillfolium) Giant ragewood (Ambrosia trifida) Fiddleneck(Amsinckia intermedia) Filaree (Erodium spp.) Fleebane (Erigeron spp.)Goldenrod (Solidago spp.) Gray rabbitbrush (Chrysothamus nauseosus)Henbit (Lamium aplexicante) Hoary vervain (Verbena stricta) Horseweed(Conyza canedensia) Indian mustard (Brassica junceea) Japanesebamboo/knotweed (Polygonum cuspidatum) Knotweed prostrate (Polygonumaviculare) Kochia (Kochia sooparia) Lambsquarters (Chenopodium album)Little mallow (Malva parviflora) Mikeweed (Ascelipas spp.) Minerslettuce (Montia perfollata) Nottleleaf goosefoot (Chenopodium murale)Oxeye daisy (Chrysanthenum leucantherum) Pepperweed (lepidum spp.)Pigweed (Amaranthus spp.) Plantain (Plantego spp.) Pokeweed (Phytolaccaamericana) Primrose (Cenothera kunthiana) Puncturevine (Tribulusterrestris) Purple loose strife (Lynthrum salicaria) Purslane (Portulacaspp.) Pusley, Florida (Richardia scabra) Rocket, London (SisymbriumIrio) Rush skeletonweed (Chondrilla juncea) Russian knapweed (Centaurearepans) Russian thistle (Saisol kali) Saltbush (Atriplex spp.)Shephered's purse (Capsella bursa-pastoris) Silverleaf nightshade(Solanum elesagnifolum) Smartweed (Polygonum spp.) Sorrel (Rumex spp.)Sowthistle (Sonchus spp.) Spurge annual (Euphorbia spp.) Stinging nettle(Urtica dioica) Sunflower (Helianthus spp.) Tansymustard (Descurainiapinnata) Sweet clover (Melitotus spp.) Texas thistle (Cirsium texanum)Velvetleaf (Abutilon theophrasti) Western ragwood (Ambrosiapalliostachya) Wild carrot (Daucus carota) Wild letture (Lactuca spp.)Wild parship (Pastinaca sativa) Wild turnip (Brassica campestris)Woolyleaf bursale (Ambrosia grail) Yellow starthistle (Cantaureasolstialis) Yellow woodsorrel (Oxalis stricta)

The invention is further illustrated by the following examples.

EXAMPLES Imazapyr Uptake and Translocation

The enhanced herbicidal effect is directly correlated to the uptake andthe translocation of the herbicidal mixture according to the inventionin plants

In the following experiments the uptake was tested. v/v means volume byvolume. ARSENAL® and CHOPPER® are Tradenames of BASF Corporation. MSOmeans methyllated seed oil.

Example I Methodology

Arsenal AC Soluble Liquid (SL) herbicide was combined with differentsurfactants at two rates (0.25% and 2% v/v) and compared to Arsenal ACand Chopper Soluble Liquid (SL) herbicide without surfactant or with12.5% MSO.

Arsenal AC is a surfactant free formulation of imazapyr containing 0.48kg ai/l I. Chopper contains an emulsifier and 0.24 kg ai imazapyr perliter.

MSO is approximately 0.85 kg/l seed oil and 0.15 kg/l nonionicsurfactant.

Rates used were 0.71 l Arsenal AC and 1.42 l Chopper, equivalent to 0.84kg imazapyr per hectare.

The surfactants are: PLURAFLO® L-1060 or KLEARFAC® AA-270

Treatments were applied to water oak (Quercus nigra). Water oak is arelatively hard to control species.

Plants were presprayed with cold formulations at 24 gram per hectarewithin a few hours of radiotracer application. Once the pre-spray dried,two of the uppermost fully expanded leaves received 2.4 μl ofradiolabeled formulation. One hour after application (HAT), one treatedleaf was removed and washed with 3-5 ml distilled water rinses, with a 5ml funnel rinse collected in the same vial. The washed treated leaf wasthen bagged and frozen for later oxidation. One week after treatment(WAT) the final harvest began with removal and water washing of theremaining treated leaf (same as HAT leaf). The plant was clipped at theroot collar and the above ground portion oven dried (stem). The rootswere washed of potting soil and oven dried. Once dried, the above- andbelow-ground plant portions were ground in a coffee mill and subsampled.

The water wash was analyzed using a 1 ml aliquot combined withScintiverse II liquid scintillation cocktail, counted on a Packard TriCarb 2900 TR Liquid Scintillation Counter (LSC). The treated leaves wereoxidized in an OX-500 Harvey Biological Oxidizer, which convertscarbon-14 to CO₂ in liquid to be counted on the LSC. The stem and rootsubsamples were also oxidized on the OX-500 and counted.

Imazapyr Uptake and Translocation Results

Experiment 1.1: KLEARFAC ® AA-270 Response vs. Water oak (Quercus nigra)Species Rate Adjuvants Washoff Root + Stem Leaf Water oak 0.00% Noadjuvants 62 2.2 27.1 0.25% Klearfac AA 270 54 2.3 37.0 2.00% KlearfacAA 270 31 3.3 53.0

Imazapyr Uptake. Numbers in the table above are the percent of appliedimazapyr. Washoff numbers are for the one week after treatmentassessment.

Conclusion

Phosphate esters reduce the washoff while increasing the root+stem andleaf concentration of imazapyr. Improved Root+Stem and Leaf uptake arenoted with increased rate of KLEARFAC® AA-270.

Experiment 1.2: Pluronic Block Polymers + Phosphate Esters vs. ImazapyrUptake. PLURAFLO 1060: Washoff* Root + Stem Leaf KLEARFAC 0.25% 2.0%0.25% 2.0% 0.25% 2.0% Species AA270 Ratio % of applied Water 100:0  5461 2.0 3.3 33.5 27.0 oak 90:10 59 57 2.1 4.0 29.7 33.6 70:30 59 59 2.33.0 31.5 30.6 50:50 48 45 2.1 2.9 39.5 42.1  0:100 54 32 2.3 3.4 36.952.1 No adjuvant 62 62 2.2 2.2 27.1 27.1 *Washoff, Root + Stem and Leafnumbers are for the one week after treatment assessment.

Conclusions:

Phosphate esters and blends with Pluronic type surfactants reduce thewashout while increasing the root+stem and leaf concentration ofimazapyr. A blend of Pluraflo 1060 and Klearfac AA 270 providesincreased uptake. For example, in the wash off, root+stem, and leafimprove with increased concentration of the adjuvant.

Example II Imazapyr Absorption Methodology

Arsenal® AC herbicide was combined with different surfactants at onerate (50% v/v), alone and with 1.0% v/v MSO. This was compared toChopper® herbicide without surfactant alone and with 1.0% v/v MSO.

Arsenal AC is a surfactant free formulation of imazapyr containing 0.48kg/l. Chopper contains an emulsifier and 0.24 kg/l imazapyr per gallon.MSO is approximately 0.85 kg/l seed oil and 0.15 kg/l nonionicsurfactant.

The absorption was measured by the relative percent of injury comparedto Chopper alone and with MSO. Rates used were 320 g activeingredient/ha. Treatments were applied to imi-tolerant sunflowers, arelatively hard to control species. The surfactants are listed below:

ID Code Surfactant Chemical Description Provider A-4 Berol DGR 81 Casteroil based Akzo Nobel blended surf. B-4 Klearfac AA 270 Alcoholalkoxylate BASF Corpora- phoshate ester tion B-6 Plurafac RA 20 Linearalcohol BASF AG ethoxylate

Imazapyr Absorption Results

Formulation without MSO % Increase Absorption Form ID 7 DAT 20 DAT Check0 0 Chopper 0 0 A-4 30.0 10.0 B-4 69.7 76.3 B-6 33.3 40.0

Formulation Plus MSO % Increase Absorption Form ID 7 DAT 20 DAT Chopper60.0 40.0 B-4 80.0 73.3

1-14. (canceled)
 15. A herbicidal mixture, comprising a) a herbicidallyeffective amount of an imidazolinone herbicide selected from the groupconsisting of imazamox, imazapic, imazapyr; b) an adjuvant comprising atleast one of the following components: a partial phosphoric ester or apartial sulfuric ester of a monohydroxy-functional polyalkyl ether andoptionally c) a further additive.
 16. The herbicidal mixture of claim15, wherein the imidazolinone herbicide is imazapyr, imazamox or amixture thereof.
 17. The herbicidal mixture of claim 15, wherein theimidazolinone herbicide is imazapyr.
 18. The herbicidal mixture of claim15, wherein the adjuvant is a partial phosphoric ester of amonohydroxy-functional polyalkyl ether and the further additive is analkyl polyoxyalkylene polyether.
 19. The herbicidal mixture of claim 15,wherein the adjuvant is a partial phosphoric ester of amonohydroxy-functional polyalkyl ether.
 20. A herbicidal finishedformulation comprising the herbicidal mixture of claim 15 and furtheradditives.
 21. A herbicidal composition comprising the herbicidalformulation of claim 20 and water.
 22. A process for preparing theherbicidal mixture of claim 15, comprising mixing the components a) andb) of the herbicidal mixture.
 23. A process for preparing the herbicidalformulation of claim 20, comprising mixing the components a) and b) ofthe herbicidal mixture and further additives.
 24. The process of claim22, comprising mixing water with the components a) and b) of theherbicidal mixture with or without further additives.
 25. A method forcontrolling undesirable vegetation, comprising allowing a herbicidallyeffective amount of the components a) and b) of the herbicidal mixtureof claim 15 to act separately or jointly on the plants or their habitat.26. The method of claim 25, wherein the undesired vegetation is in thepresence of trees.
 27. A method for controlling undesirable vegetationin forestry, comprising allowing a herbicidally effective amount of thecomponents a) and b) of the herbicidal mixture of claim 15 to actseparately or jointly on the plants or their habitat.